We are getting ready to replace an aging Weil McClain GV boiler with a new boiler and indirect hot water tank. I have narrowed my choice down to either a Navien NHB-80 or a HTP UFT-80, I really like the HTP but Naviens are the most popular in my area which I think is important in the years to come for service and support. I have spoken to 3 HVAC firms that all seem to have good rating on Angie's list and all seen knowledgeable, cost is not an issue they all seem reasonable. I have attached pictures from the contractor that I feel the most comfortable with. He indicated our installation will be fairly similar to the pictures below with the exception of we will have 2 heating zones and the indirect hot water tank, the tankless system was already in place when they replaced the boiler in the example. My question is does this look like a proper install and everything piped correctly? The same contractor has also mentioned going with an HTP EFTC-199F which is a floor standing combi with a built in 15 gallon indirect tank which would be great because I could use the space he said the only disadvantage is that it will only modulate down to 19.9 btu vs 8k for the Navien, He mentioned pricing would be very similar because it is less complicated to pipe. Does anyone have any experience with this unit? Your thoughts would be appreciated you guys seem to have a wealth of knowledge.